The invention pertains to optical memory cards in general, and in particular to a method for creating a fingerprint identification means on an optical memory card.
Identification cards used as credit cards, bank debit cards and the like are rapidly replacing cash as a preferred method for conducting commercial transactions. Consequently, forgery and fraudulent use of such cards is an increasing problem. Identification cards, which carry photographs, provide a fast and convenient means of identifying the authorized user. For instance, U.S. Pat. No. 4,745,268, assigned to the assignee of the present invention, describes a system in which wallet sized visually readable information, such as a face photograph, relating to a person is created on material disposed on one side of a wallet-sized card. However, fraudulent use of photographic identification cards may still occur. Such fraudulent use typically involves substitution of another photograph for that of the authorized user. Additionally, those attempting to fraudulently use the card may attempt to alter their appearance to appear more like the individual in the card identification photo. Also, the appearance of a cardholder may vary making it difficult to determine whether the card user is the rightful owner.
Fingerprints on identification cards are another means by which a card user""s identity may be verified. Traditional fingerprint identification means include ink fingerprints left on a surface of the identification card. U.S. Pat. No. 5,053,608 describes such means. Unfortunately, a traditional ink fingerprint is subject to tampering. The original fingerprint may be washed off and replaced with the fingerprint of a user attempting to fraudulently use the card.
Another method for verifying the identification of the user of an identification card involves writing a fingerprint as digital data on an optical media of the identification card for later comparison to the user""s fingerprint. Such a method provides a good means for verification. For instance, U.S. Pat. No. 4,835,376, assigned to the assignee of the present invention, describes a read and write system for personal information cards employing a laser. Unfortunately, in order to verify that the user of the card is the rightful owner of the card, an optical memory card reader/writer device is required to read any machine-readable data.
Therefore, it is an object of the present invention to provide an improved method for verifying the identification of a card user.
It is a further object of the invention to provide an improved method for creating a fingerprint identification means on an optical memory card.
The above objects are achieved by a method wherein an eye readable image of a fingerprint is laser burned onto an optical medium of an optical memory card after a cardholder leaves a fingerprint on an upper, transparent cover of the optical memory card. The fingerprint acts as a template for the image that is burned on the optical medium by refracting the laser beam at fingerprint ridges but not fingerprint valleys. After the fingerprint image has been burned on the card, the fingerprint left on the cover of the card may be removed by wiping or washing the upper cover of the card.
To create the eye readable image, the owner of the card, also called the cardholder, places his finger on the upper transparent cover of the optical memory card, the card having the optical medium disposed beneath the upper cover and above a base. When the user""s finger is pressed onto the card cover, substances, such as oil naturally found on the owner""s finger, remain on the cover in the pattern of a fingerprint having ridges and valleys. The pattern is a faithful reproduction of the pattern of ridges and valleys of the owner""s finger. Optionally, the cardholder may moisten the finger to be pressed onto the card with an additional substance before pressing the finger on the card cover.
The card is placed in a reader/writer device, known in the art, to create the fingerprint image by darkening portions of the optical medium located beneath the transparent cover with a laser beam. The laser beam is continuously scanned over the fingerprint and passes through the fingerprint valleys disposed on the transparent cover of the card to the optical medium. The laser beam darkens areas of the optical medium that are disposed beneath areas of the card corresponding to the valleys of the fingerprint. Typically, the laser beam will pass through transparent substances. Although the ridges of the fingerprint are mostly transparent, they include surfaces angled relative to the surface of the card that refract the incoming laser beam to the extent that the light no longer focuses on the intended point on the optical medium. Thus, the ridges effectively prevent the laser beam from contacting the underlying optical medium and interfere with the darkening of the medium. Light and dark areas that correspond to the pattern of ridges and valleys of the cardholder""s fingerprint are thus created. Thus, laser beam scanning and fingerprint image recording occur in a single operation.
The present invention is also advantageous in that the fingerprint image, resulting from the light and dark areas on the optical medium, may be viewed without any external apparatus. Further, the burned fingerprint image is embedded inside the card, just as data may be embedded inside the card. The optical medium is disposed behind the transparent cover, thus any attempt to fraudulently alter the optical medium will likely require removal of the cover and destruction of the card.